应用bFGF建立新型核性白内障大鼠模型的探索性研究

Age-related nuclear cataract is closely related to lens aging, but its pathogenesis is yet unclear. With aging, one typical change in lens is its constant epithelial proliferation and differentiation. Compelling evidences have shown that FGF is the only factor that can induce the process of cell differentiation, which plays a key role in keeping lens growing.Crystallin degeneration and posttranslational modification (PTM) is another change in aging lenses; this could be responsible for opacities. Studies in our group have shown that variable nuclear opacities appeared in rat lens with addition of bFGF both in vitro and in vivo. Besides, there were also some crystallin modifications with the same characteristic as age-related nuclear cataract. Therefore, with some basic methods, such as rats lens epithelial explants, 2D-electrophoresis and mass spectrum, immunofluorescence and etc, The aim of this study is to to establish a new nuclear cataract model in rats using bFGF that mimic age-related nuclear cataract and to investigate its mechanism at molecular and cellular levels. This new field of research will help to elucidate mechanism of age-related cataract and may provide a target of phar drugs..Key words: age-related nuclear cataract, animal model, basic fibroblast growth factor, crystalline degeneration.

老年性核性白内障与晶状体老化关系密切，确切发病机制不明。随年龄增长，哺乳动物晶状体发生两种典型改变：一是上皮细胞不断增殖、分化，形成纤维细胞逐层包绕在晶状体外部，使晶状体质量和体积不断增长，bFGF是维持这一生理生长的关键因子；二是晶状体蛋白逐渐出现变性及翻译后修饰，引起晶状体硬度增加、透明性下降。课题组前期应用bFGF进行大鼠晶状体离体培养和在体前房内给药，模拟促晶状体生长环境，发现晶状体出现不同程度核性混浊，部分晶状体蛋白表达水平发生改变，因此，拟在此基础上探索大鼠核性白内障的建模方法，借助大鼠晶状体囊膜片技术，双向电泳联合质谱分析，免疫荧光等方法，由细胞和蛋白水平阐明晶状体老化和白内障发生的潜在机制。本项目的实施将为核性白内障的发病机制开辟新的研究思路，以期为药物治疗提供新的靶点。

老年性核性白内障与晶状体老化关系密切，确切发病机制不明。在本项目中，课题组通过应用bFGF进行大鼠晶状体离体培养和在体前房内给药，模拟促晶状体生长环境，探索bFGF引起晶状体核性白内障的建模方法及机制；通过借助大鼠晶状体囊膜片技术，双向电泳联合质谱分析，免疫荧光等方法，由细胞和蛋白水平阐明晶状体老化和白内障发生的潜在联系和机制。本项目的研究目标包括以下三部分：1）以bFGF为干预因素，探讨建立大鼠晶状体核性浑浊的离体和在体动物模型；2）探讨大鼠晶状体浑浊的分子机制；3）从细胞水平探讨bFGF促晶状体上皮细胞增殖分化的机制。课题组基本完成上述目标，对于大鼠活体实验部分，因手术并发症较多，对实验结果影响明显，如何构建更加稳定的动物体系，仍是我们下一步工作的重点。课题组通过在器官培养液中加入bFGF，成功构建了大鼠晶状体浑浊的体外培养体系，检测并探讨了引起浑浊的主要蛋白成分。此外，通过对不同类型的人核性白内障形态及分子水平分析检测，发现核性老年性白内障细胞排列更紧密，其中特异性升高的蛋白同样在离体大鼠核性白内障模型也可检测到，验证了大鼠晶状体发生核性浑浊的现象与人老年性核性白内障具有共同之处。此外，对在体的大鼠核性白内障动物模型建模及方法探讨已获得初步结果。本项目首先建立了大鼠晶状体核性浑浊的离体培养体系，通过与人核性白内障组织在蛋白水平的对比，探讨晶状体核性浑浊的发生机制，达到预期目标。本项目的创新之处在于从动物眼晶状体正常生长发育的角度出发，研究维持晶状体生长的重要生长因子bFGF对晶状体老化及白内障发生的作用，以此为依据建立一种体外诱导晶状体核性浑浊的晶状体培养体系，为研究白内障的发病机制、预防及延缓疾病发生的治疗方法提供理论依据。